From line has ()

[hermit921]

Just ran into an odd problem.  The new Exchange server here seems to reject 
any message with parentheses () in the body From line.  It rejects as 
"sender denied", after the entire message has been seen by Exchange, as 
soon as I type in the period.  OK, idiot misleading error message, but I 
want to know if this violates any of the smtp RFCs?  Or is anyone 
unfortunate enough to know if this is an Exchange configuration setting?

hermit921